This invention relates to enclosures for cable splices for mechanical protection of the splice and for providing a barrier against water and moisture intrusion into the splice.
A variety of enclosures for cable splices are presently in use, including electrical and optical cables with a plurality of conductors. After the conductor interconnections are completed and the appropriate insulation or other protection has been applied, a housing is positioned around the splice with some form of sealing compound in the housing. The sealing compound usually is a gel which functions to reduce penetration of moisture into the splice. The housing itself provides mechanical protection for the splice and is normally designed to be removable for reentering the splice.
In one type of enclosure, the housing is partially filled with the sealing compound before it is positioned around the splice. Some form of end seal is provided to close the open ends of the housing around the cables which extend from each end of the splice. In another type of enclosure, an opening is provided in the wall of the housing for pouring the sealing compound into the interior of the housing after it is positioned around the splice. This type of construction, usually referred to as gravity encapsulation, tends to leave many openings and paths in the sealing compound through which moisture can penetrate.
In another type of encapsulation, a bag or wrap of some nature is positioned around the splice and filled with a sealing compound by pouring or the like. Then the encapsulated splice is tightly wrapped with overlapping turns of tape to apply pressure to the sealing compound within the bag to force the sealing compound into the interstices to provide a more effective barrier against moisture. While this type of encapsulation is reasonably effective, it is not easy to install, requiring considerable time and considerable skill to achieve a highly moisture-resistant closure.
Another approach for a quality encapsulation is to utilize a caulking gun or the like for injection of sealing compound into the interior of the housing after it is positioned around the splice with the end seals in place. With this system, considerable pressure can be exerted on the sealing compound to urge the compound into the various spaces. However, this method requires an extra tool and space for operating the tool.
The current designs for cable splice enclosures are shown in greater detail in the publications of the manufacturers, including AT&T, 3M, Raychem, Thomas & Betts and Communications Technology Corporation.